Airbag assembly

ABSTRACT

An airbag includes a rear panel, a front panel, and an extension panel. The rear panel has an inflation aperture for receiving an inflation gas. The front panel has at least one communication aperture, and the front panel is connected to the rear panel at a peripheral seam to define a primary inflatable portion having a central axis. The extension panel has an inner edge that is connected to the front panel at a location that is offset from the central axis of the primary inflatable portion and an outer edge that is connected to at least one of the front panel or the rear panel to define a secondary inflatable portion that is in communication with the primary inflatable portion through the at least one communication aperture. When inflated by the inflation gas, the secondary inflatable portion extends outward with respect to the front panel toward a vehicle occupant.

TECHNICAL FIELD

The disclosure relates to the field of inflatable restraints forautomobiles.

BACKGROUND

Inflatable restraint devices commonly called airbags are standardequipment on most new vehicles. In early implementations of airbagsystems, vehicles were equipped with one or more airbags that woulddeploy from forward-facing regions such as the steering wheel and thepassenger side of the instrument panel. In more recent implementations,additional airbags have been employed in different areas of the vehicle.For example, side-curtain airbags have been utilized to provide enhancedenergy dissipation capacity along the sides of vehicles. Side-curtainairbags have been employed in areas adjacent to the roof rail andheadliner or the side doors. These airbag devices are typicallyconcealed from occupant view prior to deployment by interior trim panelsassociated with the roof rail and/or headliner.

When an airbag is deployed, it is inflated with a gas, which pressurizesthe airbag and induces surface tension in the material from which theairbag is fabricated. To ensure that the airbag deploys correctly, guidefeatures are sometimes provided to allow the tensioned material to movein a desired manner with respect to adjacent vehicle structures, such astrim panels, structural pillars, windows, and seats.

SUMMARY

Airbag assemblies for use in vehicles are taught herein.

One aspect of the disclosed embodiments is an airbag assembly thatincludes a rear panel, a front panel, and an extension panel. The rearpanel has an inflation aperture for receiving an inflation gas. Thefront panel has at least one communication aperture. The front panel isconnected to the rear panel at a peripheral seam to define a primaryinflatable portion having a central axis. The extension panel has aninner edge that is connected to the front panel at a location that isoffset from the central axis of the primary inflatable portion and anouter edge that is connected to at least one of the front panel or therear panel to define a secondary inflatable portion that is incommunication with the primary inflatable portion through the at leastone communication aperture. When inflated by the inflation gas, thesecondary inflatable portion extends outward with respect to the frontpanel toward a vehicle occupant.

Another aspect of the disclosed embodiments is an airbag assembly thatincludes a steering wheel, an inflator connected to the steering wheelfor providing an inflation gas during inflation, a rear panel, a frontpanel, and an extension panel. The rear panel has an inflation aperturefor receiving the inflation gas from the inflator. The front panel hasat least one communication aperture. The front panel is connected to therear panel at a peripheral seam to define a primary inflatable portionhaving a central axis. The extension panel has an inner edge that isconnected to the front panel at a location that is offset from thecentral axis of the primary inflatable portion and an outer edge that isconnected to at least one of the front panel or the rear panel to definea secondary inflatable portion that is in communication with the primaryinflatable portion through the at least one communication aperture. Thesecondary inflatable portion is adapted to receive the inflation gas viathe primary inflatable portion and, when inflated by the inflation gas,extends outward with respect to the front panel toward a vehicleoccupant.

Another aspect of the disclosed embodiments is airbag assembly thatincludes a steering wheel, an inflator connected to the steering wheelfor providing an inflation gas during inflation, a rear panel, a frontpanel, and an extension panel. The rear panel has an outer periphery andan inflation aperture for receiving the inflation gas from the inflator.The front panel has at least one communication aperture, an outerperiphery of the front panel that is connected to the outer periphery ofthe rear panel at a peripheral seam to define a primary inflatableportion that has a central axis. When inflated by the inflation gas, theprimary inflatable portion is wider than the steering wheel and definesan occupant-facing surface around the central axis of the primaryinflatable portion. The extension panel is substantially toroidal andhas an inner edge that is connected to the front panel at a locationthat is offset from the central axis of the primary inflatable portionand an outer edge that is connected to the front panel and the rearpanel at the peripheral seam to define a secondary inflatable portionthat is in communication with the primary inflatable portion through theat least one communication aperture. The secondary inflatable portion isadapted to receive the inflation gas via the primary inflatable portionand, when inflated by the inflation gas, the secondary inflatableportion extends outward with respect to the front panel toward a vehicleoccupant, is positioned closer to the vehicle occupant than theoccupant-facing surface of the primary inflatable portion, and is widerthan the primary inflatable portion.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawingswherein like referenced numerals refer to like parts throughout theseveral views, and wherein:

FIG. 1 is a side view of an interior of a vehicle equipped with a driverairbag assembly and a curtain airbag assembly.

FIG. 2 is a top view of the interior of the vehicle during deployment ofthe driver airbag assembly and the curtain airbag assembly.

FIG. 3 is a side view of the interior of the vehicle during deploymentof the driver airbag assembly and the curtain airbag assembly.

FIG. 4 is a top cross-section view showing the curtain airbag assemblyduring deployment of the curtain airbag assembly.

FIG. 5 is a side cross-section view showing the driver airbag assemblyprior to deployment of the driver airbag assembly.

FIG. 6 is a side cross-section view showing the driver airbag assemblyduring deployment of the driver airbag assembly.

FIG. 7A is a first example configuration for a secondary inflatableportion of the driver airbag assembly.

FIG. 7B is a second example configuration for the secondary inflatableportion of the driver airbag assembly.

FIG. 7C is a third example configuration for the secondary inflatableportion of the driver airbag assembly.

FIG. 7D is a fourth example configuration for the secondary inflatableportion of the driver airbag assembly.

FIG. 7E is a fifth example configuration for the secondary inflatableportion of the driver airbag assembly.

DETAILED DESCRIPTION

Vehicle airbags are placed at locations within a vehicle that areadjacent to the vehicle occupants and are oriented relative to thevehicle occupants so as to maximize the likelihood that the vehicleoccupant will contact the center of the airbag during deployment of theairbag in response to rapid deceleration of the vehicle. In somesituations, however, the motion of the vehicle occupants duringdeployment of the airbag is such that the vehicle occupant does not comeinto contact with the center of the airbag but rather comes into contactwith a peripheral part of the airbag. The disclosure herein relates inpart to airbag assemblies where an airbag includes a secondaryinflatable portion that is located near the periphery of a primaryinflatable portion. The disclosure herein is also directed to airbagassemblies in which the secondary inflatable portion of a first airbagis engageable with a second airbag during deployment of the airbags.

FIGS. 1-3 show a vehicle 10 having an impact restraint system thatincludes a driver airbag assembly 100 and a curtain airbag assembly 200.The vehicle 10 may include a front door 14 and a rear door 16, each ofwhich including one or more windows 17. The front door 14 and the reardoor 16 can be separated from one another by an interior structuralpillar or B-pillar 18 of the vehicle 10. A front structural pillar orA-pillar 20 is disposed forward of the front door 14. A rear structuralpillar or C-pillar 22 is disposed rearward of the rear door 16. TheA-pillar 20, the B-pillar 18, and the C-pillar 22 can each be covered bytrim panels. Front seats 24 are positioned adjacent to the front door14, while rear seats 26 are positioned adjacent to the rear door 16. Ofcourse, the driver airbag assembly 100 and the curtain airbag assembly200 could be used with other vehicles, such as vehicles that do notinclude a rear door 16 but include rear seats 26, or vehicles that lackboth a rear door 16 and rear seats 26.

The driver airbag assembly 100 and the curtain airbag assembly 200 areconfigured to be deployed upon rapid deceleration of the vehicle 10(e.g., during an impact event or other contact between the vehicle 10and an exterior obstacle) to restrain motion of the occupants of thevehicle 10 with respect to the vehicle 10 and to dissipate energy fromthe force of the impact. The vehicle 10 can include sensors,controllers, and associated hardware (not shown) that sense an impactevent, determine whether to deploy the airbag assembly in response tothe impact event, and cause deployment of the airbag assembly.

Prior to deployment, the driver airbag assembly 100 and the curtainairbag assembly 200 are disposed in a pre-deployment position (FIG. 1).In the pre-deployment position the driver airbag assembly 100 and thecurtain airbag assembly 200 can be hidden from view within the interiorthe vehicle 10. The airbags of the driver airbag assembly 100 and thecurtain airbag assembly 200 can be folded, rolled, or otherwisecompressed into a compact state when they are disposed in thepre-deployment position. For example, in the illustrated embodiment, thedriver airbag assembly 100 is disposed within a steering wheel 27 of thevehicle 10 and the curtain airbag assembly 200 is disposed at leastpartially behind a headliner 28 of the vehicle 10 and extends underneaththe headliner 28 along the longitudinal direction of the vehicle 10,just above the front door 14 and the rear door 16 as well as theB-pillar 18.

During deployment of the driver airbag assembly 100 and the curtainairbag assembly 200, a portion of each airbag assembly is inflated.Inflation causes at least part of each airbag assembly to enter thepassenger compartment of vehicle 10. In order to inflate the driverairbag assembly 100 and the curtain airbag assembly 200, a firstinflator 102 can be associated with the driver airbag assembly 100 forproviding an inflation gas to an airbag of the driver airbag assembly100, and a second inflator 202 can be associated with the curtain airbagassembly 200 for providing an inflation gas to an airbag of the curtainairbag assembly 200.

FIGS. 2-3 show the interior of the vehicle 10 during inflation of thedriver airbag assembly 100 and the curtain airbag assembly 200, with thedriver airbag assembly 100 and the curtain airbag assembly 200 in theirinflated conditions. In particular, FIG. 2 is a top view showing theinterior of the vehicle 10 during inflation of the driver airbagassembly 100 and the curtain airbag assembly 200, and FIG. 3 is a sideview of the interior of the vehicle 10 during inflation of the driverairbag assembly 100 and the curtain airbag assembly 200.

The driver airbag assembly 100 includes an airbag that is defined by aprimary driver airbag portion 110 and a secondary driver airbag portion120. Herein, the primary driver airbag portion 110 may also be referredto as a primary inflatable portion of the driver airbag assembly 100,while the secondary driver airbag portion 120 may also be referred to asa secondary inflatable portion of the driver airbag assembly 100. Wheninflated, the secondary driver airbag portion 120 extends outward froman occupant-facing surface 112 of the primary driver airbag portion 110.

The curtain airbag assembly 200 includes a primary curtain portion 210and a secondary curtain portion 220. Herein, the primary curtain portion210 may also be referred to as a primary inflatable portion of thecurtain airbag assembly 200. The secondary curtain portion 220 may alsobe referred to as a secondary inflatable portion of the curtain airbagassembly 200. The primary curtain portion 210 defines an occupant-facingsurface 212. When inflated, the secondary curtain portion 220 extendsoutward from the occupant-facing surface 212 of the primary curtainportion 210 of the curtain airbag assembly 200.

The secondary curtain portion 220 of the curtain airbag assembly 200 ispositioned with respect to the secondary driver airbag portion 120 ofthe driver airbag assembly 100 to allow interaction of the secondarycurtain portion 220 and the secondary driver airbag portion 120 duringinflation of the driver airbag assembly 100 and the curtain airbagassembly 200. In particular, when the driver airbag assembly 100 and thecurtain airbag assembly 200 are inflated, the relative position of thedriver airbag assembly 100 with respect to the curtain airbag assembly200 allows the secondary driver airbag portion 120 to come intoengagement with the secondary curtain portion 220 of the curtain airbagassembly 200. Thus, the distance by which the secondary curtain portion220 extends outward from the occupant-facing surface 212 over theprimary curtain portion 210 is sufficient to allow at least a portion ofthe secondary curtain portion 220 to contact at least a portion of thedriver airbag assembly 100. For instance, the distance by which thesecondary curtain portion 220 extends outward from the occupant-facingsurface 212 of the curtain airbag assembly 200 can be equal to orgreater than the distance between the occupant-facing surface 212 of theprimary curtain portion 210 of the curtain airbag assembly 200 and thesecondary driver airbag portion 120 of the driver airbag assembly 100,in some implementations.

In some implementations, the secondary curtain portion 220 is engageablewith the secondary driver airbag portion 120 opposite theoccupant-facing surface 112 of the primary driver airbag portion 110 ofthe driver airbag assembly 100. In this implementation, the secondarycurtain portion 220 can be positioned longitudinally forward withrespect to the secondary driver airbag portion 120, where longitudinallyforward is defined as being closer to the front of the vehicle in afront-to-rear direction of the vehicle. In other examples, the secondarycurtain portion 220 can be positioned longitudinally rearward withrespect to the secondary driver airbag portion 120, where longitudinallyrearward is defined as being further away from the front of the vehicle10 in a front-to-rear direction of the vehicle. In either of theseexamples, the secondary curtain portion 220 can also be positionedlaterally adjacent to the secondary driver airbag portion 120 of thedriver airbag assembly 100.

As shown in the illustrated example in FIG. 3, the secondary curtainportion 220 can be relatively short in the front-to-rear direction ofthe vehicle as compared to the overall length of the curtain airbagassembly 200. In the illustrated example, the secondary curtain portion220 has a height that is less than the overall height of the primarycurtain portion 210 of the curtain airbag assembly 200 and is tallerthan the height of the secondary driver airbag portion 120 of the driverairbag assembly 100. It should be understood, however, that thesecondary curtain portion 220 of the curtain airbag assembly 200 neednot be taller than the secondary driver airbag portion 120 of the driverairbag assembly 100. For instance, an alternative implementation of asecondary curtain portion 222 (shown in FIG. 3) can be substantiallycylindrical.

FIG. 4 is a cross-section view of the curtain airbag assembly 200showing the primary curtain portion 210 and the secondary curtainportion 220. The curtain airbag assembly 200 includes an exterior panel230 and an interior panel 240. When the curtain airbag assembly 200 isinflated, the exterior panel 230 is oriented toward the exterior of thevehicle. When the curtain airbag assembly 200 is inflated, the interiorpanel 240 is oriented toward the interior of the vehicle 10. Theexterior panel 230 and the interior panel 240 are connected to oneanother at a peripheral seam 214 and cooperate to define the primarycurtain portion 210 of the curtain airbag assembly 200. In addition, theoccupant-facing surface 212 of the primary curtain portion 210 is formedon the interior panel 240.

The curtain airbag assembly 200 also includes a curtain extension panel250. The curtain extension panel 250 is connected to the interior panel240 at a seam 252 that extends continuously around a periphery 254 ofthe curtain extension panel 250. The secondary curtain portion 220 isdefined by cooperation of the interior panel 240 with the curtainextension panel 250, thereby defining an inflatable interior space forthe secondary curtain portion 220 between the interior panel 240 and thecurtain extension panel 250. In order to allow inflation gas to enterthe secondary curtain portion 220, at least one communication aperture,such as a communication aperture 260, extends through the interior panelto allow fluid communication between the interior of the primary curtainportion 210 and the secondary curtain portion 220. Thus, duringinflation, the inflation gas enters the curtain airbag assembly 200 fromthe second inflator 202 (FIG. 1) by first entering the primary curtainportion 210 and then entering the secondary curtain portion 220 from theprimary curtain portion 210 through the communication aperture 260.

FIG. 5 is a cross-sectional view of the steering wheel 27 showing thedriver airbag assembly 100 in a pre-deployment condition. Prior todeployment, the driver airbag assembly 100 is deflated with the primarydriver airbag portion 110 and the secondary driver airbag portion 120folded and disposed within a driver airbag housing 104, which is aportion of the steering wheel 27 and is arranged around a central axis,which is the axis around which the primary driver airbag portion 110 isarranged, and the axis along which the primary driver airbag portion 110inflates during inflation of the driver airbag assembly 100. The firstinflator 102 can, in some implementations, be disposed within the driverairbag housing 104. The driver airbag housing 104 can be closed by apanel 108 that is configured to open, break, separate, or otherwiseexpose the primary driver airbag portion 110 and the secondary driverairbag portion 120 to the interior of the vehicle during inflation ofthe driver airbag assembly 100.

FIG. 6 is a cross-sectional view showing the steering wheel 27 and thedriver airbag assembly 100 in the inflated condition, subsequent todeployment of the driver airbag assembly 100. The driver airbag assembly100 can include a rear panel 130, a front panel 140, and an extensionpanel 150. When the inflation gas is received from the first inflator102 during inflation of the driver airbag assembly 100, the rear panel130 and the front panel 140 cooperate to define the primary driverairbag portion 110, while the front panel 140 and the extension panel150 cooperate to define the secondary driver airbag portion 120.

The rear panel 130 can be a substantially circular member having aninflation aperture 132 that is located centrally on the rear panel 130for receiving the inflation gas from the first inflator 102. The rearpanel 130 also includes an outer periphery 134, which can besubstantially circular in shape. The rear panel 130 can be joined to thefront panel 140 and the extension panel 150 at a seam 160. The seam 160can have three layers, one for each of the rear panel 130, the frontpanel 140, and the extension panel 150, that are joined in any suitablemanner, such as by sewing or by adhesives. In one implementation, aportion of the extension panel 150 can be interposed between the rearpanel 130 and the front panel 140 at the seam 160.

The front panel 140 can be a substantially circular panel having anouter periphery 142 that is located adjacent to the seam 160. One ormore communication apertures 144 can extend through the front panel 140to allow fluid communication of the inflation gas from the interior ofthe primary driver airbag portion 110 to the interior of the secondarydriver airbag portion 120.

The extension panel 150 is arcuate in shape and is located adjacent tothe periphery of the primary driver airbag portion 110 which is definedadjacent to the seam 160 where the rear panel 130 and the front panel140 meet. In some examples, the extension panel 150 is substantiallytoroidal, while in other examples, the extension panel 150 defines anarc with a first end and a second end, as will be explained furtherherein. The extension panel 150 has an inner edge 152 that is connectedto the front panel 140 at an inner seam 154. The inner seam 154 isoffset from the central axis 106. The extension panel 150 also has anouter edge 156, which can be a peripheral edge of the extension panel150. The outer edge 156 of the front panel 140 can be located adjacentto the seam 160, where the extension panel 150 is connected to the frontpanel 140 and the rear panel 130.

When the driver airbag assembly 100 is inflated, the inflation gas flowsinto the primary driver airbag portion 110 via the inflation aperture132. The primary driver airbag portion 110 is defined by the rear panel130 and the front panel 140. The inflation gas travels from the interiorof the primary driver airbag portion 110 into the interior of thesecondary driver airbag portion 120 via the communication apertures 144.The secondary driver airbag portion 120 is defined by the front panel140 in cooperation with the extension panel 150. When inflated by theinflation gas, the secondary driver airbag portion 120 extends outwardwith respect to the front panel 140 of the driver airbag assembly 100toward a vehicle occupant. In addition, when inflated, at least aportion of the secondary driver airbag portion 120 is positioned closerto the vehicle occupant than the occupant-facing surface 112 of theprimary driver airbag portion 110. In some implementations, wheninflated, at least a portion of the secondary driver airbag portion 120is positioned radially outward from the seam 160 with respect to thecentral axis 106.

As shown in FIGS. 7A-7E, multiple configurations can be adopted for thesecondary driver airbag portion 120 of the driver airbag assembly 100.As shown in FIG. 7A, the secondary driver airbag portion 120 can besubstantially toroidal and extend continuously around the periphery ofthe primary driver airbag portion 110. As shown in FIG. 7B, an alternatesecondary driver airbag portion 320 can extend from a first end 322 to asecond end 324 along the outer periphery of the primary driver airbagportion 110. In FIG. 7B, the alternate secondary driver airbag portion320 extends along an arc of approximately a half circle with respect tothe periphery of the primary driver airbag portion 110. FIGS. 7C, 7D,and 7E are examples in which multiple instances of the alternatesecondary driver airbag portion 320 are provided, where each extendsalong a portion of the periphery of the primary driver airbag portion110. As shown in these examples, the alternative secondary driver airbagportion 320 can be provided in multiple configurations that includesecondary inflatable portions that are spaced apart from one another andare provided in any desired number.

In some examples, the primary driver airbag portion 110 of the driverairbag assembly 100, when inflated, is wider than the steering wheel 27.In addition, this secondary driver airbag portion 120, when inflated,can be wider than the primary driver airbag portion 110 of the driverairbag assembly 100.

In operation, the airbag assemblies described herein are deployed byinflating at least a portion of the airbag panel of the airbag assembly.

While the description herein is made with respect to specificimplementations, it is to be understood that the invention is not to belimited to the disclosed implementations but, on the contrary, isintended to cover various modifications and equivalent arrangementsincluded within the spirit and scope of the appended claims, which scopeis to be accorded the broadest interpretation so as to encompass allsuch modifications and equivalent structures as is permitted under thelaw.

What is claimed is:
 1. An airbag comprising: a rear panel having aninflation aperture for receiving an inflation gas; a front panel havingat least one communication aperture, and the front panel is connected tothe rear panel at a peripheral seam to define a primary inflatableportion having a central axis; and an extension panel having an inneredge that is connected to the front panel at a location that is offsetfrom the central axis of the primary inflatable portion and an outeredge that is connected to at least one of the front panel or the rearpanel to define a secondary inflatable portion that is in communicationwith the primary inflatable portion through the at least onecommunication aperture and, when the primary inflatable portion isinflated by the inflation gas, a portion of the inflation gas passesthrough the at least one communication aperture to inflate the extensionpanel such that the extension panel extends outward with respect to thefront panel toward a vehicle occupant, the front panel defines anoccupant-facing surface around the central axis of the primaryinflatable portion, the occupant-facing surface of the front panel isexposed to the vehicle occupant, and at least part of the extensionpanel is disposed farther from the inflation aperture of the rear panelin a direction parallel to the central axis than a furthest portion ofthe occupant-facing surface of the front panel at full inflation.
 2. Theairbag of claim 1, wherein the outer edge of the extension panel isconnected to at least one of the front panel or the rear panel adjacentto the peripheral seam.
 3. The airbag of claim 1, wherein the outer edgeof the extension panel is connected to the front panel and the rearpanel at the peripheral seam.
 4. The airbag of claim 1, wherein thefront panel has an outer periphery and the rear panel has an outerperiphery, wherein the outer periphery of the front panel, the outerperiphery of the rear panel, and the outer edge of the extension panelare connected at the peripheral seam.
 5. The airbag of claim 1, whereinthe extension panel is substantially arcuate and extends along a portionof the peripheral seam.
 6. The airbag of claim 1, wherein the extensionpanel is substantially toroidal.
 7. The airbag of claim 1, wherein, wheninflated, at least a portion of the secondary inflatable portion ispositioned closer to the vehicle occupant in a direction parallel to thecentral axis than the occupant-facing surface of the primary inflatableportion.
 8. The airbag of claim 1, wherein at least a portion of thesecondary inflatable portion, when inflated, is positioned radiallyoutward from the peripheral seam.
 9. The airbag of claim 1, wherein thesecondary inflatable portion is adapted to receive the inflation gas viathe primary inflatable portion.
 10. An airbag assembly comprising: asteering wheel; an inflator connected to the steering wheel forproviding an inflation gas during inflation; a rear panel having aninflation aperture for receiving the inflation gas from the inflator; afront panel having at least one communication aperture, and the frontpanel is connected to the rear panel at a peripheral seam to define aprimary inflatable portion having a central axis; and an extension panelhaving an inner edge that is connected to the front panel at a locationthat is offset from the central axis of the primary inflatable portionand an outer edge that is connected to at least one of the front panelor the rear panel to define a secondary inflatable portion that is incommunication with the primary inflatable portion through the at leastone communication aperture, is adapted to receive the inflation gas viathe primary inflatable portion and, when the primary inflatable portionis inflated by the inflation gas, a portion of the inflation gas passesthrough the at least one communication aperture to inflate the extensionpanel such that the extension panel extends outward with respect to thefront panel toward a vehicle occupant, the front panel defines anoccupant-facing surface around the central axis of the primaryinflatable portion, the occupant-facing surface of the front panel isexposed to the vehicle occupant, and an annular crest is defined by aportion of the extension panel that is disposed farthest from theinflation aperture in a direction parallel to the central axis, whereinthe annular crest is positioned farther from the inflation aperture thana furthest portion of the occupant-facing surface of the front panelfrom the rear panel in the direction parallel to the central axis atfull inflation and the annular crest is disposed radially outward fromthe peripheral seam with respect to the central axis.
 11. The airbag ofclaim 10, wherein the front panel has an outer periphery and the rearpanel has an outer periphery, wherein the outer periphery of the frontpanel, the outer periphery of the rear panel, and the outer edge of theextension panel are connected at the peripheral seam.
 12. The airbag ofclaim 10, wherein the extension panel is substantially arcuate andextends along a portion of the peripheral seam.
 13. The airbag of claim10, wherein the extension panel is substantially toroidal.
 14. Theairbag of claim 10, wherein, when inflated, at least a portion of thesecondary inflatable portion is positioned closer to the vehicleoccupant in a direction parallel to the central axis than theoccupant-facing surface of the primary inflatable portion.
 15. Theairbag of claim 10, wherein the primary inflatable portion, wheninflated, is wider than the steering wheel.
 16. The airbag of claim 15,wherein the secondary inflatable portion, when inflated, is wider thanthe primary inflatable portion.
 17. An airbag assembly comprising: asteering wheel; an inflator connected to the steering wheel forproviding an inflation gas during inflation; a rear panel having anouter periphery and an inflation aperture for receiving the inflationgas from the inflator; a front panel having at least one communicationaperture, an outer periphery of the front panel that is connected to theouter periphery of the rear panel at a peripheral seam to define aprimary inflatable portion that has a central axis and, when inflated bythe inflation gas, is wider than the steering wheel, defines anoccupant-facing surface around the central axis of the primaryinflatable portion, and the occupant-facing surface of the front panelis exposed to the vehicle occupant; and an extension panel having an arcshape, the extension panel having an inner edge that is connected to thefront panel at a location that is offset from the central axis of theprimary inflatable portion, and an outer edge that is connected to thefront panel and the rear panel at the peripheral seam to define asecondary inflatable portion that is in communication with the primaryinflatable portion through the at least one communication aperture, isadapted to receive the inflation gas via the primary inflatable portionand, when inflated by the inflation gas, extends outward with respect tothe front panel toward a vehicle occupant, is at least partiallydisposed farther from the inflation aperture of the rear panel in adirection parallel to the central axis than a furthest portion of theoccupant-facing surface of the front panel at full inflation, ispositioned closer to the vehicle occupant in a direction parallel to thecentral axis than the occupant-facing surface of the primary inflatableportion, is wider than the primary inflatable portion, and extends in anarc along a first portion of the peripheral seam.
 18. The airbagassembly of claim 17, wherein a second portion of the peripheral seam isfree from connection to the extension panel.
 19. The airbag assembly ofclaim 17, wherein the extension panel extends along an arc that definesat least a half-circle from the first end to the second end.